Trujillo is a diminutive woman, her attorney Jack Carroll said in court, while her boyfriend was much bigger. When an argument allegedly broke out that night, and she tried to defend herself, she grabbed the closest weapon at hand -- her high heel.

In a video of her police interrogation that was played at the trial, Trujillo told investigators her boyfriend had attacked her in a rage and that she had to defend herself.

While Trujillo said she fought back in self defense, the prosecution said she never once told the 911 dispatcher or police she was in danger.

"Self defense is only when you are in fear for your life. When did we hear that Ana was in fear for her life? Never," the prosecutor said in closing arguments.

A neighbor reported hearing a man scream at 2:13 a.m., but never heard a woman yell, the prosecutor said.

Andersson's friends described the University of Houston medical researcher as kind and mild-mannered.

"Dr. Andersson probably was a nice guy, but what he did that night can't be dismissed because he was a nice guy," Trujillo's defense attorney said during closing arguments, insisting that Andersson attacked Trujillo.

The jury is expected to hear more evidence in the punishment phase on Wednesday before deciding on a sentence for Trujillo. She faces up to life in prison.